The present invention relates to a combination rack for holding a computer mainframe and at least one expansion unit, and more particularly to such a combination rack which comprises two side frames and at least one partition frame coupled between the side frames, the at least one partition frame each having a longitudinal through hole through which a bus line is inserted.
In order to increase the capability of a computer, expansion cards may be plugged into the computer. Because a computer has a limited number of sockets for receiving expansion cards, an expansion unit is needed to receive extra cards. When a computer system and an expansion unit are used, the user may directly put the computer mainframe of the computer system and the expansion unit on the top of the computer table, and then connect a bus line between the computer mainframe and the expansion unit for signal transmission. This arrangement cannot keep the computer mainframe and the expansion unit firmly in place.